Cored plastics profiles and manufacture of frames for windows and the like therefrom

ABSTRACT

This invention is concerned with cored extruded plastics profiles, suitable for use in the manufacture of frames for windows and the like, comprising a core of shape-retaining material and a cladding of plastics material extruded therearound. The invention is also concerned with methods of manufacturing frames for windows or the like from such profiles, including methods of forming the corner joints of said frames, and with glazing clips particularly suitable for use in assembling glass or other panels in said frames.

BACKGROUND ART

Frames for windows and the like have traditionally been made from wood,and the manufacturing process has often involved fairly complexmachining operations both in providing the frame members with thedesired profile and in forming the corner joints of the frames. Thesemachining operations result in a considerable wastage of material.Furthermore wooden frames require frequent painting to avoid rapiddeterioration from exposure to the weather.

As an alternative to wood, it is also well-known to manufacture framesfor windows and the like from aluminium, which may be extruded toprovide suitable profiles, usually of complex cross-sectional shape,which may be cut into frame members of the desired length and assembledby means appropriate corner joint arrangements to provide the requiredframes. While such frames of aluminium are likely to require lessmaintenance than frames made from wood, the aluminium frames result in aconsiderably greater transmission of heat unless the profilesincorporate some form of heat barrier, which further increases thecomplexity of the profile.

In the interests of ease of manufacture, avoidance of wastage ofmaterials, economy and providing a virtually maintenance-free product ithas been proposed to construct frames for windows and the like fromwooden frame members of simple cross section (e.g. rectangular) havingcladding portions at least partially enclosing the wooden frame members,which cladding portions are conveniently made by extrusion of plasticsmaterial and are shaped to perform the necessary sealing, weatherresisting and interconnecting roles of the frame. Such cladding can bepre-coloured to perform any decorative function and is virtuallymaintenance free. The specification of my United Kingdom patentapplication No. 7924197 (published under No. 2026125 on Jan. 30, 1980)relates to the formation of corner joints between frame members andshows, in FIGS. 3 and 7 of the drawings thereof, a cross-section of aframe member (as just above referred to) having a wooden core with acladding of plastics material extruded therearound for use in theconstruction of a window frame. The corner joints as disclosed in saidspecification are made by injecting plastics material into communicatingcavities formed in abutting portions of the frame members, the plasticsmaterial being reinforced by metal inserts if desired.

It is an object of the present invention to achieve further economiesand ease in the manufacture of frames for windows and the like withsubstantially no wastage of materials by providing a cored extrudedplastics profile which is so formed and shaped that, not only can it bemanufactured very economically, to very close dimensional tolerances,and with virtually no wastage of material, but, with very simpleoperations performed thereon, can be used to assemble both an outer,static, frame and an inner, opening frame of a frame assembly for awindow or the like which may be fitted with glass or other panelmaterial and readily interconnected by hinge mechanism or the like.

DISCLOSURE OF INVENTION

According to the invention the cored extruded plastics profile ischaracterized in that the core is of generally rectangular crosssectional shape and in that the cladding provides (a) along one surfaceof the profile at a locality adjacent one edge of that surface aretaining member for a panel of glass or other suitable material, whichretaining member extends inwardly over said surface and is inclined atan angle thereto and (b) along said surface of the profile, at alocality spaced from the retaining member, a rib having an undercut faceinclined to said surface at an angle at least substantiallycorresponding to the angle of inclination of the retaining member,whereby, in the manufacture of inner and outer frames for windows or thelike from said profile, the retaining member may be cut from framemembers which are to form the outer frame and utilised as glazing stripsin the manufacture of the corresponding inner frame, the glazing stripsbeing arranged, after the insertion of a glass or other panel, to abutagainst the undercut face of the rib of the profile and to be supportedby supporting members mounted on said surface of the profile.

In the manufacture of a cored extruded plastics profile in accordancewith the invention the core may comprise any suitable material providingthe necessary strength and shape-retaining stability. Preferredmaterials for the core are a good quality laminated plywood or,alternatively, a cement-bonded fibrous material such as cement-bondedchipboard or cement-bonded glass fibres. Furthermore the cladding may beof any suitable plastics material capable of being extruded around thecore and of providing adequate strength to the glass or otherpanel-retaining member and the desired durability under adverse weatherconditions. Preferred materials for the cladding are appropriate gradesof polyvinylchloride or polycarbonates.

A profile in accordance with the invention may conveniently be made byfeeding a continuous length of core material through a plasticsextruding machine having accurately made dies which impart the desiredshape and dimensions to the cladding of the profile. It is preferred topass the core material, prior to its passage through the plasticsextrusion machine, through a coating machine which is organised to coatthe faces of the core material with a layer of hot melt adhesive whichserves to fill any pores, or small cavities in the core material with aview to avoiding difficulties in the plastics extrusion process whichmight otherwise occur by reason of expansion of gas (air) in the poresor cavities resulting in blemishes in the cladding. Preferably thecoating machine comprises scraper or doctor blades arranged to controlthe thickness of the hot melt coating so that the coated core materialis built up to a prescribed accurate dimensional form ready to enter thedies of the plastics extrusion machine.

In the manufacture of a profile in accordance with the invention, thedies of the plastics extrusion machine are preferably so shaped as toprovide the profile, along a second surface thereof (which is parallelwith the surface from which extends the panel retaining member) withflange means extending normally to said second surface and adapted, whenthe profile is assembled into said inner and outer frames, to provide aweather proofing facility.

In a profile in accordance with the invention it is anticipated that anadequate panel-retaining facility will be provided if thepanel-retaining member is inclined to the first mentioned surface of theprofile at an angle within the range of from about 30° to about 60°.Conveniently the angle is 45°.

A method of manufacturing frames for windows or the like from a coredextruded plastics profile in accordance with the invention preferablycomprises the steps of feeding an indefinite length of the profile pastsawing means organised to make a series of transverse cuts at 45° acrossthe profile so as to sever therefrom successively frame members ofappropriate lengths for assembly alternately into an outer, static,frame and an inner opening, frame for a window or the like, severing theglass or other panel-retaining members from those frame members whichare to be assembled into the outer frame, assembling the alternatemembers to form said inner frame and said outer frame, and, aftercutting the retaining members severed from the frame members for theouter frame to appropriate lengths, utilizing them as glazing strips inassembling said inner frame with a glass, or other, panel. The glazingstrips are arranged to abut against the undercut face of the rib of theprofile and to be supported by supporting members mounted on thefirst-mentioned surface of the profile, said supporting memberspreferably being provided by glazing clips each comprising a baseportion adapted to be secured to said surface of the profile, a firstpanel-abutting portion arranged to extend at least substantiallyperpendicular to the base portion for engagement with one side of thepanel and a second panel-abutting portion which extends from an endportion of the base portion inwardly thereover for engagement with theother side of said panel, said second panel-abutting portion providing asupporting surface for the glazing strip, the glazing strip beingconveniently secured thereto by means of pressure-sensitive adhesiveprovided on said supporting surface. Conveniently the glazing strips areformed of extruded plastics material such as polythene, polyethylene,polypropylene or polycarbonate. Preferably the glazing clips are soconstructed that a mid portion of the base portion is provided withinclined, stepped, wedge faces which are adapted to lie adjacent to anedge face of the glass, or other, panel and are arranged to co-operatewith wedge members having complementary stepped wedge faces which may bedriven between said edge of the panel and the stepped wedge faces of theglazing clip to support the panel at a desired position with respect tothe profile.

In a slightly modified form of profile also in accordance with theinvention an inner end portion of the panel-retaining member is providedwith a rib portion which extends towards the first-mentioned surface ofthe profile (over which the panel-retaining member extends) andterminates in a substantially cylindrical bead spaced from that surface,and the profile also includes an intermediate rib which extends alongsaid surface at a locality between the panel-retaining member and thefirst-mentioned rib, said intermediate rib having undercut inclinedfaces at its opposite sides. In using the slightly modified form ofprofile in the construction of frames for windows and the like theglazing strips are arranged, after insertion of a glass or other panel,to abut against the undercut face of the first-mentioned rib of theprofile and to be supported by glazing clips each of which comprises apair of leg portions adapted to clip over the undercut faces of theintermediate rib and a pair of arm portions providing between them asemi-cylindrical recess adapted to clip around the bead of the glazingstrip.

In the manufacture of frames from a profile in accordance with theinvention the corners are preferably made by utilizing corner jointswhich are made by injecting plastics material into communicatingcavities formed in abutting portions of the frame members, the cornerjoints being of improved construction as compared with those disclosedin my U.K. patent application No. 2026125 above referred to. It will beappreciated that when a length of the profile is cut, as hereinbeforereferred to, by said transverse cuts to provide the several framemembers, the cuts provide the frame members with inclined end faceswhich, in forming a corner joint between two adjacent frame members, arebrought into abutting relationship. The preferred form of corner jointis made by drilling two series of at least substantially parallel boresthrough the inclined end faces of the frame members, the bores in eachseries being arranged to overlap, to provide a pair of slot-likecavities having walls with ridges extending into each frame memberthrough its inclined end face. The two series of bores are drilled atsuch localities that the cavities of each pair of cavities are spacedapart in a direction extending widthwise of the respective framemembers, and the lengthwise direction of each slot-like cavity lies atleast substantially parallel to a plane containing the two assembledframe members, the cavities being so located that a cavity in one framemember communicates with the corresponding cavity in the other framemember when the frame members are held in abutting relationship. Duringthe assembly of the frame members there is introduced, into each pair ofcommunicating cavities, a plate-like reinforcing member having aplurality of apertures extending therethrough, and, while the framemembers are firmly held in assembly position, a settable plasticsmaterial is injected into said cavities at least substantially to fillthose cavities and enter the apertures in the reinforcing membertherein, so as to provide, on setting of the plastics material, abridging member extending from a cavity in one frame member to thecorresponding cavity in the adjacent frame member so as to secure theframe members together. Conveniently the reinforcing members are formedfrom expanded metal sheet material. It will be appreciated that theridged walls of the cavities and the apertures in the reinforcing memberplaced therein provide means with which the plastics material keys onsetting, thus providing a good anchorage for the components forming thejoint. Preferably the bores providing each cavity are arranged to extendinto the associated frame member in a direction inclined to a normal toits end face, for example at an angle in the range of from about 10° toabout 30°. The ridges provided by the overlapping bores do not thenextend parallel to the lengthwise direction of the frame member, thusresisting further the withdrawal of the reinforced plastics materialfrom the cavity in which it is formed. Where the profile for the framemembers is made of relatively heavy material (such as the cement-boundcored profile hereinbefore referred to), the corner joints may befurther strengthened and rendered very resistant to breaking open byproviding, in each of two frame members associated with a joint, anadditional cavity extending through the inclined end face in a directionlengthwise of the frame member so that, when the frame members areassembled, these lengthwise extending cavities communicate. Inassembling the components forming the joint, an L-shaped reinforcingmember, of less cross-sectional area than the cavities, is placedtherein, plastics material then being injected into the additionalcavities. Conveniently the L-shaped reinforcing member is in the form ofa rod provided with surface indentations to provide a key for theplastics material. The plastics material may be conveniently injectedinto all the cavities at one joint simultaneously through a bore in oneend at least of the frame members communicating with each cavity, thebore preferably extending through an inside face of one of the framemembers.

While, in forming corner joints as described in the last precedingparagraph, any suitable plastics material which is capable of beingrendered fluent for injection into the cavities of the joint and thensets to provide, with the reinforcing member, a strong corner jointbridging member may be used, a particularly suitable material comprisesnylon.

It will be appreciated that, in forming joints between adjacent framemembers in the manner just above described in which the cavities in theend portions of the adjacent frame members are formed by drillingthrough the inclined end faces of the frame members, it can be assuredthat the cavities do not break through outer surfaces of the framemembers and are thus completely hidden in the completed joint.

From what has been said hereinbefore it will be appreciated that coredextruded plastics profiles in accordance with the invention may readilybe constructed in a continuous, indefinite, length by a series ofrelatively simple machines and that the form of the profile is such thatit can be economically manufactured from readily available materialswith substantially no waste. Furthermore, frames for windows and thelike can readily be constructed from such profiles by the use of aseries of relatively simple machines in such manner that there isvirtually no wastage of material. The resultant frames are likely to bestrong, of relatively simple construction, durable against deteriorationdue to atmospheric conditions and to be of low thermal conductivity,particularly when double glazed panels are assembled therein. Suchframes are likely to be very economical to manufacture, particularlysince it is anticipated that the several machines needed for themanufacture of the profile, and for the manufacture of frames therefromwill be capable of being arranged in a production line, the machinesbeing automatically controlled by a computer.

There will now be given, with reference to the accompanying drawings, amore detailed description of a cored extruded plastics profile (whichwill be described first in one form and then in a slightly modifiedform) in accordance with the invention, a method of manufacturing theprofile, a method of constructing frames for windows or the liketherefrom, and glazing clips suitable for use in assembling the framesall in accordance with the invention. It will be understood that theprofile, the method of its manufacture, the method of constructingframes therefrom, and the glazing clips have been selected fordescription by way of illustration of the invention and not by way oflimitation.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings:

FIG. 1 is a transverse section of a first form of the illustrativeprofile, the profile being a cored extrusion of indefinite length;

FIG. 2 is a diagrammatic representation of how the illustrative profilemay be cut, by means of a series of 45° cuts, into members of lengthssuitable for use in constructing a window frame comprising an outer,static, frame and an inner, opening, glass-supporting frame;

FIG. 3 is a diagrammatic representation showing how the various membersindicated in FIG. 2 are assembled into such a window frame;

FIG. 4 is a transverse sectional view, taken on the line IV--IV in FIG.3, of adjacent portions of the outer frame and inner frame of such awindow frame, in closed position;

FIG. 5 is an end view of a glazing clip used in producing the windowframe shown in FIG. 4;

FIG. 6 is a transverse sectional view of adjacent portions of the ouerframe and inner frame of a window frame generally similar to tht shownin FIG. 4 but incorporating a slightly different form of theillustrative profile and using a different form of glazing clip;

FIG. 7 is a side view of a glazing clip as used in constructing a windowframe in accordance with FIG. 6;

FIGS. 8 and 9 are, respectively, plan and front views of the glazingclip shown in FIG. 7;

FIGS. 10 and 11 are, respectively, front and top views of a wedge memberfor use with the glazing clip shown in FIG. 7;

FIG. 12 is a detail view, partly in section and partly broken away,showing two frame members connected together by means of a first form ofjoint suitable for use in making frames in accordance with theinvention;

FIG. 13 is a section of the line XIII--XIII in FIG. 12 showing thelocation of cavities in one of the frame members, the frame member beingof a more complex shape than that shown in FIG. 12;

FIG. 14 is a plan view, and FIG. 15 is an end view, of a reinforcingmember used in making the joint shown in FIG. 12;

FIG. 16 is a view, generally similar to FIG. 12, but showing a secondform of joint suitable for use in making frames in accordance with theinvention;

FIG. 17 is a section on the line XVII--XVII in FIG. 16, but againshowing a frame member similar to that of FIG. 13;

FIG. 18 is a side view, and FIG. 19 is an end view, of an additionalreinforcing member used in making the joint shown in FIG. 16.

BEST MODE OF CARRYING OUT THE INVENTION

The illustrative profile shown in FIG. 1 is a cored extruded plasticsprofile suitable for use in the manufacture of frames for windows andthe like. It comprises a core 1 of shape retaining material within acladding 3 of extruded plastics material. The profile can be readilymanufactured by a continuous extruding process and cut into lengths toprovide frame members for windows and the like in the manner hereinafterdescribed. In the interests of economy, avoidance of waste, and ease ofmanufacture, the cross sectional shape of the core is kept simple, andis generally rectangular as shown in FIG. 1. The core provides thestructure with the desired strength while the plastic cladding providesan at least substantially maintenance-free protective surface and isformed and shaped, as hereinafter described, to perform a panel (e.g.glass) retaining function and other functions such as weather proofingto be mentioned hereinafter.

As shown in FIG. 1 the core 1 is of laminated form and preferablycomprises a good quality polywood giving a high degree of dimensionalstability, freedom from warping, and, by means of multi-tongued joints,a facility for easily joining successive lengths of core material into acontinuous length for feeding into the necessary machinery by which theplastics cladding is extruded around the core. However, the core maycomprise any suitable material having the necessary structural anddimension retaining properties outlined hereinbefore. Particularlysuitable materials are cement-bound fibrous materials such ascement-bound chipboard or cement-bound class fibres which, like theplywood, can be produced as sheets of appropriate thickness which sheetsmay readily be cut into the lengths of the desired width, using multiplesawing machines of known type. The lengths of core material may then bejoined together by means of appropriate joints to form a core ofindefinite length ready for feeding into the plastics extrudingmachinery.

Before the plastics cladding is extruded around the core it is desirableto pass the core through a coating machine which coats all the faces ofthe core with a layer of hot-melt adhesive material, such layer beingindicated by the reference numeral 5 in FIG. 1 (the thickness of thehot-melt layer being somewhat exaggerated in that Figure). The layer 5of hot-melt adhesive material serves to fill any pores, small cavitiesand the like in the core with a view to avoiding difficulties in theplastics extrusion process which might otherwise occur by reason ofexpansion of gas (air) in the pores or cavities resulting in blemishesin cladding. By the use of coating machinery having scraper or doctorblades of the appropriate type the coating process can be so controlledthat the coated core is built up to a prescribed accurate dimensionalform on leaving the coating machine ready to enter the extrusionmachinery by which the plastics cladding is applied. As an example of asuitable hot-melt adhesive for the core-coating process just describedmay be mentioned hot-melts sold under the name Eastobond by EastmanChemical Products Inc., but it will be understood that other, generallysimilar, products may be used.

During the cladding process the plastics material is extruded by meansof known machinery on to the core together with a further layer ofhot-melt adhesive which assists in bonding the cladding material to thecore. During the extrusion process the core and cladding are extrudedthrough accurately made dies which impart the desired shape anddimensions to the finished profile.

It is to be understood that any plastics material may be used for thecladding 3 but, by way of example, appropriate grades ofPolyvinylchloride and Polycarbonates may be mentioned as being suitable.

The dies of the plastics cladding extrusion machine are so shaped thatthe extruded profile, in addition to providing a wall 7 covering thewhole of the core, provides also a glass, or other, panel retainingmember 9 along one edge portion (hereinafter referred to as the outeredge portion) of the upper surface of the profile as viewed in FIG. 1,an inner rib 11 along the other edge portion of said upper surface, anintermediate rib 13 extending along an intermediate portion of saidsurface as shown in FIG. 1, and two flanges 15, 17 extending normally tothe lower parallel surface of the profile as seen in that figure. Theflanges 15, 17 are adapted to provide a weather proofing facility aswill become clear hereinafter. These several members and flanges extendthroughout the length of the profile.

The panel retaining member 9 is inclined inwardly from the outer edgeportion of the upper surface of the profile at an angle a and from itsinner end portion there extends a depending rib 19 terminating in asubstantially cylindrical bead 21, the rib 19 extending at leastsubstantially perpendicularly to the upper surface of the cladding (asseen in FIG. 1). The member 9 at its upper end portion has a smallupwardly extending portion terminating in a surface 22 inclined at anangle c to the normal to the upper surface of the extrusion as seen inFIG. 1, the angle c being conveniently 60° (or substantially so) for apurpose hereinafter referred to.

The inner rib 11 is under cut as shown in FIG. 1 to provide a supportingface 23 making an angle a to the upper surface of the profile. Theintermediate rib 13 is undercut at both sides at angles b to provideinclined surfaces 25, 27 for a purpose hereinafter described.

Before indicating preferred values for various dimensions of theprofile, the way in which it may be cut and assembled into a window (orlike) frame will now be indicated with particular reference to FIGS. 2and 3. As indefinite length of profile may be fed past sawing meansorganised to make a series of transverse saw cuts (indicated at31,32,33,34,35,36,37,38 and 39 in FIG. 2) at 45° across the profile, soas to sever therefrom successively frame members A,E,B,F,C,G,D,H ofappropriate lengths for assembly alternately into an outer, static,frame and an inner, opening, frame for a window or the like. Thus, theframe members A,B,C,D indicated in FIG. 2 may be assembled to providethe inner, opening, frame 40 of a window frame as shown in FIg. 3. Thepanel retaining member 9 is then severed from the frame members E,F,G,Hby a saw cut extending parallel and close to the adjacent surface of thecladding as indicated by the dotted line 41 in FIG. 4 and these framemembers are then assembled to form said outer, static, frame 42 as shownin FIG. 3. Preferably the ribs 11 and 13 will have also been removedfrom those frame members by similar saw cuts to provide a reasonablysmooth surface to the outside of the static frame 42 ready for insertioninto an aperture in a wall of a building.

In FIG. 4 a portion of a sealed double glazed panel is indicated inphantom by the reference numeral 43. It is supported between theretaining member 9, which has a sealing strip 45, conveniently offlexible PVC, attached to the depending rib 19 at the outside of theglass and, at the inside, a glazing strip 9' provided by material of theretaining member 9 which has been severed from the frame members for theouter frame 42 and cut to appropriate length. The glazing strip 9' isarranged to abut against the undercut face 23 of the rib 11 and isretained in position by being supported by supporting members mounted onthe upper surface of the profile as seen in FIG. 4. The supportingmembers comprise a series of glazing clips 47 (one of which is shown inFIG. 5) placed at intervals along the intermediate rib 13. The glazingclips 47 are shaped as shown in FIG. 5 and are conveniently made ofnylon, the length perpendicular to the plane of the drawing of each clipbeing of the order of 20 mm. As shown in FIG. 5 each clip comprises abody portion 49 having a pair of depending leg portions 51 havinginwardly directed toe portions with inclined surfaces complementary tothe surfaces 25, 27 of the intermediate ribs 13 of the profile. Theglazing clip also comprises a pair of arm portions 53 extending upwardlyfrom the body portion and provided with a semi-cylindrical recess 57commensurate with the diameter of the bead 21 of the depending rib 19 ofthe panel retaining member 9 of the profile. The inner sides of the armsinclude inclined faces 55 leading to the recess 57. The dimensions ofthe glazing clip are such that, by squeezing together the arm portions53, the leg portions 51 may be separated and clipped over theintermediate rib 13 of the profile, conveniently at about 200 mmintervals therealong. Then, with the glass panel in place, the glazingstrip (indicated by the reference 9' in FIG. 4) is inserted by tuckingit under the face 23 of the inner rib 11 and pressing its upper portiondownwardly so that the bead 21' of the depending rib 19' is forcedbetween the inclined surfaces 55 of the arm portions 53 into therecesses 57 in which the bead is then firmly held. When the glazingstrip 9' has been so inserted, it is preferable that an upper endportion of the adjacent arm portion 53 of each glazing clip engages theinner side of the glazing strip to help hold the parts firmly in place.Beads of silicone 59 inserted between the glass panel and the retainingmember 9 and glazing strip 9' seal the system against the ingress ofdirt and moisture. The inclined surface 22 (FIG. 1) reduces any risk ofcontaminating the main face of the portion 9 when trimming the siliconebead.

When the window frame arrangement is to support a double glazed unitcomprising two sheets of 4 mm glass sealed with a gap of 12 mm (thuspresenting an overall thickness of 20 mm) convenient values for thevarious dimensions indicated in FIG. 1 by identifying letters are givenin the following table:

    ______________________________________                                        letter   Description            mm                                            ______________________________________                                        d        depth of body of profile                                                                             27.0                                          e        height of member 9     20.0                                          f        depth of flanges 15, 17                                                                              11.0                                          g        spacing between flanges 15, 17                                                                       20.0                                          h        width of base of rib 11                                                                              4.0                                           i        spacing between roots of surfaces 23, 25                                                             17.0                                          k        inward spacing of flange 15                                                                          7.0                                           l        overall width of profile                                                                             67.0                                          m        depth of ribs 11, 13   1.5                                           n        thickness of root of rib 13                                                                          1.5                                           p        spacing of bead 21 from top surface                                                                  8.5                                           q        diameter of bead 21    2.5                                           r        projected width of member 9                                                                          19.0                                          t.sub.1  thickness of side walls of cladding                                                                  1.0                                           t.sub.2  thickness of top and bottom walls                                                                    0.5                                           t.sub.3  thickness of flanges 15, 17                                                                          2.5                                           t.sub.4  thickness of member 9  2.5                                           t.sub.5  thickness of depending rib 19                                                                        1.5                                           ______________________________________                                    

In a profile having the dimensions given in the above table the angle a(inclination of the panel retaining member 9, and the correspondinginclination of the undercut face 23 of the rib 11) as shown in FIG. 1 is45° or substantially so. However, with appropriate changes in certaindimensions of the profile, it is anticipated that the angle could bewithin a range of from about 30° to about 60° while still providing anadequate panel retaining facility. Conveniently the angles b and c mayboth be of the order of 60° but it will be understood that these anglesare not particularly critical.

The window frame assembly adjacent portions of inner and outer frames ofwhich are shown in cross section in FIG. 6 is made from a cored extrudedplastics profile which is generally similar to that hereinbeforedescribed with reference to FIG. 1 but is modified in certain details aswill now be explained. The profile thus comprises a core 1 with aplastics cladding 3 of extruded plastics material which also provides aglass, or other, panel retaining member 9 inclined inwardly at an angleof 45° (or substantially so) from an outer edge of the upper surface ofthe profile (as viewed in FIG. 6) and an inner rib 11, having anundercut face, along an inner edge portion of said upper surface of theextrusion. The profile shown in FIG. 6 also includes flanges 15 and 17generally similar to those of the profile shown in FIG. 1. However theretaining member 9 does not include a depending rib and bead such as therib 19 and bead 21 of the profile shown in FIG. 1. Neither does theupper surface of the profile shown in FIG. 6 include an intermediate ribsuch as the rib 13 of the profile shown in FIG. 1.

The method of cutting and assembling the frame members of the frameassembly shown in FIG. 6 is generally similar to that hereinbeforedescribed with reference to FIGS. 2,3, and 4 except that, while theglazing strips 9' (severed from the outer frame members as hereinbeforedescribed) are supported in abutting relationship with the undercut faceof the rib 11 of the inner frame members, they are supported bysupporting members provided by glazing clips 100 of differentconstruction from those hereinbefore described.

Each glazing clip 100 is conveniently formed of extruded plasticsmaterial such as polythene or polyethylene or polypropylene orpolycarbonate and comprises a base portion 101 of generally rectangularoutline, as seen in plan (FIG. 8). Where a double glazing unit ofoverall thickness of some 20 mm is to be supported the overall width, w,of the base portion may conveniently be of some 52 mm and the length, y,may conveniently be some 25 mm. Upstanding from the base portion 101 isa first glass-abutting portion 103 which is conveniently formedperpendicularly (or substantially so) to the base portion 101 at alocality spaced inwardly from one end portion of the base portion so asto provide a tongue 105. The glazing clip comprises a secondglass-abutting portion 107 which extends inwardly at an angle of 45° (orsubstantially so) from the other end of the base portion 101. An outer,inclined, face 109 of the portion 107 is provided with a layer ofpressure-sensitive adhesive for a purpose hereinafter described. Anupper end portion 111 (as seen in FIG. 7) of the glass-abutting portion107 is flexible and formed to provide a glass-engaging seal member. Amid portion of the base portion 101 is provided with inclined, stepped,wedge faces 113, 115 which, when the glazing clip is in use, lieadjacent to an edge face of the glass (or similar) panel to be supportedby the glazing clip. Wedge members 117, one of which is shown in FIGS.10 and 11, having stepped wedge faces 119 complementary to the faces 113and 115 of the glazing clip may be driven between the edge face of theglass (or other) panel and the faces 113 and 115 to support the panel atthe desired position with respect to the glazing clip and hence a framemember on which the clip is mounted, conveniently by a screw 121extending through a lug 123 formed on the base portion of the glazingclip.

The glazing clips are secured (at appropriate intervals) along the uppersurface of the inner frame member as shown in FIG. 6 so that theirtongues 105 extend under the glass retaining member 9, the firstglass-abutting portions 103 engage the outer face of a glass panel P andthe second glass-abutting portions 107 engage the inner face of thepanel. The inclined faces 109 provide support for the glazing strip 9'the base portion of which is tucked under the inner rib 11 and thepressure-sensitive adhesive on the faces 109 serves to secure theglazing strip in place. Wedges 117 driven in between the glass panel Pand the wedge faces 113 and 115 of the glazing clip support the panel Pin the desired position. Beads of sealing material 59 serve to seal thejoints between the glass panel and the glass retaining member 9 andglazing strip 9'.

In assembling frame members into frames corner joints between adjacentframe members are preferably made in a manner which will now bedescribed. Each frame member 201, 203 (represented in somewhatsimplified form in FIG. 12) is provided with end faces 205 which, at acorner, are brought into abutting relationship along a plane representedby the dotted line 206 to form a mitre joint. Prior to assembly of theframe members a pair of slot-like cavities 207 is formed in each end ofeach frame member so as to extend through the inclined end faces 205,the cavities being spaced apart in a direction extending widthwise ofthe respective frame members as shown in FIG. 13. As will be seen fromFIGS. 12 and 13 the slot-like cavities 207 are so formed that theirlengthwise direction lies at least substantially parallel to a planecontaining the two frame members when assembled together.

The cavities are so located in the frame members that each cavity in oneframe member communicates with a corresponding cavity in the other framemember when they are brought together with their end faces 205 inabutting relationship. During assembly of the frame members there isintroduced into each pair of communicating cavities a plate-likereinforcing member 211 having a plurality of apertures 212 extendingtherethrough, the reinforcing member preferably being formed fromexpanded metal sheet material. The outline shape of each reinforcingmember is such that, when it is introduced into a pair of communicatingcavities it is substantially co-extensive therewith (see FIG. 12). Theabutting frame members 201 and 203 are then firmly clamped togetherwhile a settable plastics material 213 is injected into thecommunicating cavities 207 at least substantially to fill those cavitiesand enter the apertures 212 in the reinforcing member(s) 211 therein. Onsetting, the plastics material 213 (with reinforcing member 211 embeddedtherein) provides a bridging member which extends from the cavity in oneframe member to the corresponding cavity in the adjacent frame member soas to secure the frame members together. The plastics material isinjected into the cavities through a cross bore 214 extending throughone of the frame members from an inside face 215 thereof. The cavities207 are conveniently formed by drilling a series of at leastsubstantially parallel bores through the end faces 205 of the framemembers 201, 203 the axes of the bores forming the cavity through theleft hand face 205 of the frame member 201 seen in FIG. 12 beingindicated by the series of parallel dot-dash lines 209. The bores arearranged to overlap (see FIG. 13) to provide a ridged formation in theside walls of the cavity, some of the resulting ridges being indicatedat 210 in FIG. 13. The ridges provide good keying with the plasticsmaterial on setting thereof in the cavities. The bores forming thecavity in an end portion of a frame member are drilled to a controlleddepth so that they do not break through any outside surface of the framemember. While the bores may be drilled perpendicular to the inclined endface 205 of the frame member if desired, a cavity of greater depth (fora given size of frame member) can be obtained by drilling the bores in adirection inclined at an angle φ (FIG. 12) to a normal to that end face(the direction of the inclination being towards the lengthwise axis ofthe frame member), the angle φ preferably being in the range of fromabout 10° to about 30° to said normal. By drilling the bores at an angleas just referred to, rather than parallel to the lengthwise direction ofthe frame member, the result is achieved that the ridges 210 of the inthe cavity walls extend somewhat obliquely with respect to the length ofthe frame member to increase the resistance to lengthwise withdrawal ofthe plastics material from the cavity.

While the form of corner joint shown in FIGS. 12 and 13 is likely to beadequately strong for many applications, a modified form of joint, shownin FIGS. 16 and 17, may be provided where even greater resistance tobreakage is desired. In the modified form of joint each of the two framemembers forming the joint is provided, additionally to the cavities 207,with a cavity 220 extending through its end face 205 in a directionlengthwise of the frame member so that, when the frame members areassembled, the additional cavities 220 communicate and are provided withan L-shaped reinforcing member 222 of somewhat less cross-sectional areathan the cavities 220, settable plastics material is injected into thecavities 220 to fill the space remaining between the reinforcing memberand the cavity walls. By arranging the cross bore 214 to communicatewith each of the cavities 207 and 220 (see FIG. 17) the plasticsmaterial may be injected into all the cavities at a jointsimultaneously.

While any plastics material capable of being rendered fluent forinjection into various cavities and settable to produce bridging membersof the required strength and durability may be used in carrying out amethod in accordance with the invention Nylon may be quoted as anexample of a suitable plastics material. Furthermore, in assembling theframe members to form a joint the abutting faces 205 may be coated withadhesive further to strengthen and seal the joint.

The cavities 220 are conveniently provided by drilling a single roundbore into each frame member and the reinforcing member 222 (seeparticularly FIGS. 18 and 19) conveniently comprises a piece of steelrod provided with surface indentations 223 to provide good keying withthe plastic material. Corner joints in the form shown in FIGS. 16 and 17are considered to be particularly suitable when profiles having cores ofcement-bound fibrous material are used since the frames made therefromare likely to be considerably heavier than when made from profiles coredwith plywood. Joints of this form are likely to be particularlyresistant to opening or coming apart in use, in view of the fact thatany tendancy for separation to occur parallel to the lengthwisedimension of a frame member (i.e. by movement parallel to a limb of thereinforcing member 222) is resisted by the action of the reinforcingmembers 211 and associated plastics material in the ridged bores(inclined to said lengthwise dimension) providing the cavities 207 andvice versa. It may be pointed out that while the profiles having coresof cement-bound fibrous materials are likely to be considerably heavierthan equivalent profiles having plywood cores, it is likely that theywill be considerably cheaper to produce, thus enabling a further economyin manufacture of frames therefrom to be achieved.

It will be appreciated that when the static and opening frames arearranged with the flanges 15, 17 and 15', 17' positioned as indicated inFIG. 4 the opening frame may be top hung or side hung. Alternativelyside pivot stay hinges may be used in which case the opening frame isarranged to move bodily outwards as it swings about a virtual transversepivot so that the window moves towards a substantially horizontalposition to facilitate cleaning. In this case the special stay hingesare housed within the spaces provided between the flanges 15 and 15',the flanges 17 and 17' being slotted where necessary. The adjacentflanges 17 and 17' are provided with sealing strips 61 (see also FIG. 1)of flexible PVC which are compressed when the window is closed toprovide draught proofing. These sealing strips may be formed andattached to the flange 17 during extrusion of the profile (as in thecase of the sealing strip 45 above referred to).

If the window frame is to be of the simple transverse pivot hinged typethe static frame members may be reversed with the flanges 15' and 17'positioned opposite the flanges 15 and 17 in which case the side framemembers are separated to a greater extent to accomodate the pivot hingesand the flanges 17 are arranged to close against stop members formed inpart on the static frame and in part on the moving frame in well knownmanner. The arrangement shown in FIG. 6 shows a "side-opening" hinge157. Also shown in FIG. 6 is a sill member 149 fixed to the static frame42 by means of metal or other brackets 151, the joint between the sillmember and the frame being sealed at 153.

Where a frame is to be glazed with a single pane of glass a differentspacing is required between the panel retaining member 9 and the glazingstrip 9', in which case the profile may be provided with an undercut ribgenerally similar to the rib 11 (see FIG. 1) but located at anintermediate position of the upper surface of the profile approximatingto the location of the intermediate rib 13 shown in that Figure. Glazingclips of the form shown in FIGS. 8 and 9 may be used with such a profilewith the spacing between the glass-abutting portions 103, 107 suitablychanged.

I claim:
 1. A cored extruded plastics profile suitable for use in themanufacture of frames for panels including wndows and comprising a coreof shape-retaining material and a cladding of plastics material extrudedtherearound, characterized in that the core (1) is of generallyrectangular cross sectional shape and in that the cladding (3) provides(a) along one surface of the profile at a locality adjacent one edge ofsaid surface a retaining member (9) for a panel, which retaining member(9) extends inwardly over said surface and is inclined at an anglethereto and (b) along said surface of the profile, at a locality spacedfrom the retaining member, a rib (11) having an undercut face (23)inclined to said surface at an angle at least substantiallycorresponding to the angle of inclination of the retaining member (9),the retaining member (9) being severable from the profile to form theprofile into an outer frame (42) and being utilized as glazing strips(9') in the manufacture of a corresponding inner frame (40), the glazingstrips (9') being arranged, after the insertion of a panel, to abutagainst the undercut face (23) of the rib (11) of the profile and to besupported by supporting members (47) mounted on said surface of theprofile.
 2. A profile in accordance with claim 1 characterized in thatthe retaining member (9) is inclined to said surface of the profile atan angle within the range of 30° to 60°.
 3. A profile in accordance withclaim 2 characterized in that said angle is substantially 45°.
 4. Aprofile in accordance with claim 1 characterized in that the core (1)comprises laminated plywood.
 5. A profile in accordance with claim 1characterized in that the core (1) comprises a cement-bonded fibrousmaterial.
 6. A profile in accordance with claim 4 characterized in thatthe core (1) comprises cement-bonded chipboard.
 7. A profile inaccordance with claim 1 characterized in that the core (1) comprisescement-bonded glass fibres.
 8. A profile in accordance with claim 1characterized in that the plastics material of the cladding comprisespolyvinylchloride.
 9. A profile in accordance with claim 1 characterizedin that the plastics material of the cladding comprises a polycarbonate.10. A profile in accordance with claim 1 characterized in that thecladding (3) also provides, along a second surface of the profileparallel with said one surface, flange means (15, 17) extending normallyto the second surface and adapted, when the profile is assembled intosaid inner and outer frames (40, 42), to provide a seal.
 11. A profilein accordance with claim 1 characterized in that an inner end portion ofsaid retaining member (9) is provided with a rib portion (19) whichextends towards said surface of the profile and terminates in a bead(21) spaced from said surface, and in that along an intermediate portionof said surface there extends an intermediate rib (13) having undercutinclined faces (25, 27).